Portillo's could fetch $1 billion

Portillo Restaurant Group Inc., the parent of beloved Chicago-area hot dog chain Portillo's Hot Dogs Inc., said today it has agreed to a strategic investment by Boston-based private-equity firm Berkshire Partners. Terms of the deal were not disclosed.

"Berkshire Partners will work closely with Dick Portillo, founder of Portillo's, to support the growth of the company," Portillo's said in a statement.

“Portillo's is my life's work and I remain committed to ensuring the continued growth and success of the business," Mr. Portillo said in the statement. "I was seeking an experienced partner that shared our vision for the company and an appreciation for our culture. After careful consideration, Berkshire Partners proved to be the best choice. I look forward to working together to further strengthen our company.”

Portillo's announced in April it was exploring a sale of its fast-casual division and that it had hired Minneapolis-based investment firm Piper Jaffray & Co. as a financial adviser.

The Oak Brook-based company's main chain, Portillo's Hot Dogs, is a household name in the Windy City, known for its Chicago-style hot dogs and Italian beef sandwiches. Mr. Portillo, started Portillo's in 1963 as a hot dog stand in Villa Park.

“We've enjoyed significant growth over the past 50 years, experiencing same-store sales increases over the last 10 years in the Chicagoland area, even when the economy as a whole suffered,” he said in April.

“This is a thriving business poised to launch to the next level, presenting an incredible opportunity for employees and investors.”

Portillo's has 38 fast-casual locations in Illinois, Indiana, California and Arizona. The company said it brought in more than $300 million in revenue in 2013.

Other restaurants owned by Portillo's include Barnelli's Pasta Bowl, Luigi's House and Honey-Jam Cafe. The company over the years has grown steadily, expanding to suburbs including Aurora, St. Charles and Crystal Lake in the early 2000s and opening locations in other states, like California, in 2005.